Centrifugal pump



Feb. 6, 1934. I o. JACOBSEN CENTRIF'UGAL PUMP Filed March 15 INWENTOR Ovans/N dncoasE-N ATTORNEY 7 :5. A 6 a 3 P W H m n 2 4 i/5 B m 1 m Q 9-om 6 l /C .9 8 a 2 I I/ 9.- w I 3 Patented Feb. 6, 1934 UNITED STATESCENTRIFUGAL PUMP Oystein Jacobson, Dayton, Ohio, assignor to The DurironCompany, Inc., a corporation of New York Application March 15, 1933.Serial No. 660,845

1 Claim.

The invention relates to self-priming centrifugal pumps and involves animprovement over the construction of my Patent No. 1,755,217, datedApril 22, 1930. The object of the invention is to 5 provide a simplifiedconstruction which will give a self-priming action, which is equally asefiective as that secured by the structure of my prior patent, and inwhich there is no interference to the inflow of water through the inleteye, such as that offered by the circulation nozzle of my patent whichhas its outlet end located in the center of the eye. Two embodiments ofthe invention are illustrated in the accompanying drawing, wherein:

Figure 1 is a vertical section through a centrifugal pump of the closedrunner or impeller type with my improvement applied thereto. And Fig; 2is a vertical section through a pump of the open runner type with theimprovement applied thereto.

In both forms of apparatus, the principal of operation is the same asthat set forth in my patent. The operation of the runner carries thepriming water in the suction elbow up into a separation pipe or chamberabove the runner. Provision is made to permit water from this elevatedbody to flow back into the pump to a point near the center of the runnerand discharge to the stream of water flowing outward along the impellervanes or passages from the center thereof to their periphery; Thisprovides a continuous circulation of the priming water which picks upsome additional airfrom the suction elbow each time it makes itscircuit, so that the elbow is finally freed from air and filled withwater, thus completing the priming operation. In the present apparatus,provision is made for conducting the gravity flow of liquid from theseparation chamber to a cavity or chamber at one side of the impellerand thence through ports in the impeller to the spiral passages of therunner, in-

stead of conducting the water back into the suction elbow through areturn nozzle as is done in my patent. Referring to Fig. 1 of thedrawing, 1 and 2 are parts of the pump casing which are bolted orclamped together; 3 is the drive shaft provided at one end with theimpeller or runner 4, which in this instance, is of the closed typehaving the usual spiral passages 5 separated by the walls or vanes 51:,and at the other end having suitable driving means (not shown), such asa pulley; and 6 is the suction elbow located in the casing 65 part 2,and having at its upper end a priming opening provided with a cover '7suitably secured 'in place.

with annular flanges 16 and 17, whose peripheries are spaced away fromthe walls of the casing members to provide the passages 19 and 19 topermit a gravity flow of liquid from the separation chamber 9 and thevolute through the annular spaces 18a and 19a provided by the spacing ofthe periphery of theimpeller from the inner wall of the pump casing tothe central portion of the pump for priming purposes, as laterdescribed. The hubs 13 and 14 are cored out, as indicated at 20 and 21,and these recesses communicate at their inner ends with the spiralrunner passages 5 via the ports 22 and 23, Provi-, sion is thus made fora flow of liquid from the passages 18 and 19 to the inner ends of therunner passages via the recesses 20 and 21 and the ports 22 and 23.

When the pump is primed, the liquid lies at about the level A,fillingthe elbow and the volute. The pump is then started, and theaction of the runner withdraws the liquid in the elbow and forces it upto a higher level in the separa tion chamber 9, such movement of theliquid carrying with it some of the air in the elbow 6. The headpressure built up in the chamber 9, due to the rise of the leveltherein, now causes a gravity flow through the annular passages 18 and19 to the front and rear sides of the impeller and thence through therecesses 20 and 21 and ports 22 and 23 to the inner ends of the impellerpassages 5, where the liquid is picked up and caused to flow up into theseparation chamber again. Provision is thus made for a repeatedcirculation of the priming liquid in a circuit including the separationchamber, the casing of the pump at the sides of the impeller and theimpeller, passages; and this movement of the liquid carries with it someof the air from the elbow 6. This quickly exhausts the air from theelbow, causing it to fill with liquid from the inlet end of such elbow,thus completing the priming operation. After the priming operation iscompleted, there is little backflow through the passages 18 and 19, asthe liquid now flowing through the volute at considerable velocitycauses a drag which counteracts the gravity flow which would otherwiseoccur. The eficiency of the pump is thus only slightly reduced incidentto the self-priming construction.

In the Fig. 2 construction, an impeller or run ner 24 of the open typeis used, such runner being provided with the usual spiral vanes 25 withpassages 26 therebetween. In this case, the drive v shaft 2'7 isintegral with the impeller, and is made tight by the stufiing box 28.The casing is in two parts 29 and 30 bolted or clamped together, thepart 30 being provided with the suction elbow 31 discharging to the eyeof the pump. The volute 32a discharges into a separation chamber 32having a discharge outlet and a priming passage 34 leading via thepassage 35 to a cavity 36. Ports 3'7 permit the priming water to flowthrough the impeller to the passages between the vanes 25. A passage 38provides a means for drainage whereby any dirt collecting in the voluteis washed into the lower end of the passage 34.

The operation of the Fig. 2 construction is similar to that described inconnection with Fig. 1. When the pump is started, the priming liqquidflows up into the separation chamber from which a return circulationoccurs through the passages 34 and 35, the cavity 36 and the ports 37,the liquid then being again carried up into the separation chamber bythe impeller. This repeated circulation finally clears the suction elbowof air so that it fills with liquid, thus completing the primingoperation.

What I claim is:

In combination in a centrifugal pump, a casing having an inlet eye atits center and a volute around its periphery, a suction elbow leading tothe eye, a separation chamber above the volute to which the volutedischarges, a runner or impeller of the closed type having vanes withpassages therebetween mounted for rotation in the casing with it'scenterin opposition to said eye and arranged to receive the liquid supplied tothe eye, a drive shaft, a hub on each side of the runner, said driveshaft being secured to one of said hubs, and each hub having an annularchamber concentric with the drive shaft and provided at its inner endwith ports leading to the passages between the vanes, a bearing on eachside of the runner in which the respective hubs are mounted, a cavity inthe casing on each side of the runner concentric with the drive shaftwith which the outer ends of said annular chambers communicate, andcommunications between the separation chamber and said cavities.

O. JACOBSEN.

